Method for controlling macroinvertebrates

Abstract

A method of controlling the fouling potential of macroinvertebrates, such as mollusks, in aqueous systems which comprises adding to the system an effective controlling amount of a water-soluble quaternary ammonium salt having the following structure: ##STR1## wherein R 1 is an alkyl group having about 6 to 24 carbons; R 2 is an alkyl, aryl or arylalkyl group having about 6 to 24 carbons; R 3 and R 4 are alkyl groups having about 1 to 4 carbons; and X is chloride, bromide, sulfate, bisulfate, nitrate or acetate. Preferably, the quaternary ammonium salt is water-soluble alkyl dimethyl benzyl ammonium chloride having an alkyl chain length from C 6 to C 24 and, most preferably, it has an alkyl distribution of about 40% C 12 , 50% C 14 and 10% C 16 .

What we claim is: 
     
       1. A method for controlling the fouling potential of Asiatic clams in a fresh water system of the type prone to such fouling, said method consisting essentially of adding to said fresh water system an effective amount to control said Asiatic clam-based fouling of a water-soluble alkyl dimethyl benzyl ammonium chloride having an n-alkyl distribution of about 40% C 12 , 50% C 14 , and 10% C 16  said alkyl dimethyl benzyl ammonium chloride compound being capable of killing at least a portion of said Asiatic clams within a 72-hour period of time after an initial exposure of up to about 24 hours to said compound. 
     
     
       2. A method according to claim 1 wherein said fresh water system is the fresh water system of a cooling water system.